1. Field of the Invention
The present invention is directed to the field of ring laser gyros, and, in particular, to a ring laser gyro employing an embedded radio frequency pumping apparatus.
2. Discussion of the Prior Art
Presently ring laser gyros (RLGs) utilize a D.C. discharge in order to start and maintain laser beams within a discharge cavity. In such use, D.C. electrodes must be in direct contact with the gain medium of the laser. In order to prevent leakage of external materials around these D.C. electrodes, an interfacial seal is used to bond the electrodes to the laser block. The integrity of such interfacial seals has historically limited the temperature range, reliability, and lifetime of RLGs employing the seals.
Often the gain necessary to sustain the laser beams in an RLG require discharge currents which are powerful enough to sputter cathode material into the gain medium. This sputtering contaminates the gain medium which results in shortening the laser lifetime and hence gyro reliability and performance. Additionally, the cathode or cathodes, depending upon the RLG configuration, pump gases from the gain medium producing undesirable gas mix changes.
European Patent Publication No. EP 0320 102 A1, having a filing date of Oct. 25, 1988, disclosed by John Albert Geen and entitled "Ring Laser Gyroscopes", discloses a ring laser gyroscope which employs a capacitively coupled RF energy through discharge to maintain the gyro. The gyroscope as disclosed by Geen is a block of Zerodur or the like generally having the shape of a cube. Electrodes transmitting the RF energy are deposited onto the outer surface of the cube.
In contrast to the prior art as disclosed by Geen, the present invention employs an inductive coil wrapped around one leg of the bore and a ring laser gyro and which is embedded in the gyro block itself. An alternate embodiment of the present invention provides a capacitively coupled RF apparatus wherein one leg of the gain bore is juxtaposed between the plates which are embedded in the gyro block itself.
In contrast to the prior art, the apparatus provided by the present invention couples radio frequency (RF) energy into the gain medium of a ring laser gyro using embedded components. The present invention thereby provides an apparatus for eliminating the need for the electrodes and their associated seals. Thus, alleviating inherent lifetime and reliability limitations found in the prior art.